My thanks to everyone who responded. Obviously the path of smaller format has already been well trodden. Even so, it seems that birding is difficult.......

Given that I already have DSLR gear, I think I'll probably try that route first, especially since the Nikon 1 V2 (which I prefer over the V1) is new and at its highest price point. It's not an inexpensive camera and I'd have to buy a Nikon AFS 70-200 or 300/4 lens as well. And the FT1. That's no small outlay for a very specific type of shooting. OTOH it could ceratinly become a future option.

To be honest what swung me into thinking about smaller sensors at all was reading about the difficulties of birding with APSC and then seeing some shots from the latest super-zoom bridge cameras. Some of them have pretty impressive reach, and with effective OIS, at least in good light, the IQ extracted from these tiny sensors is amazing. The 1 system's 1" sensor should do even better with a good quality lens.